AD5590BBCZ datasheet(29/44 Pages) AD

29 / 44 page

AD5590

Rev. 0 | Page 29 of 44

Reference Section

An external reference source should be used to supply the 2.5 V

reference to the ADC. Errors in the reference source results in

gain errors in the ADC transfer function and adds to the specified

full-scale errors of the ADC. A capacitor of at least 0.1 μF should

be placed on the VREFA pin. Suitable reference sources for the

ADC include the AD780, REF193, and the AD1852.

If 2.5 V is applied to the VREFA pin, the analog input range can

either be 0 V to 2.5 V or 0 V to 5 V, depending on the range bit

in the control register.

AMPLIFIER SECTION

The operational amplifiers in the AD5590 are micropower,

rail-to-rail input and output amplifiers that feature low supply

current, low input voltage, and low current noise.

The parts are fully specified to operate from a single 5.0 V

supply, or ±2.5 V dual supplies. The ability to swing rail-to-rail

at both the input and output enables designers to buffer CMOS

ADCs, DACs, ASICs, and other wide output swing devices in

low power, single-supply systems. The amplifiers in the AD5590

are fully independent of the DAC and ADC sections. If some or

all of the amplifiers are not required, connect them as a

grounded unity-gain buffer, as shown in Figure 59.

Figure 59. Configuration for Unused Amplifiers

AD5590BBCZ Datasheet(PDF) 29 Page - Analog Devices